A couple of key points made from Quinn Hillyer's obituary of Treen:
This is a a big legacy for a man who lost most of his big elections:
Dave Treen, Political Builder
David Connor Treen was a one-term governor (and four-term congressman) of a troubled southern state. He lost or withdrew from far more elections than he won. His nomination for a federal appeals court judgeship fell apart. And he was the butt of two of the most famous put-downs in American political history. Yet, although almost no history books will say so, he was one of the more consequential figures in late 20th century politics, not just in Louisiana, but nationally.
The losing was inseparable from the big accomplishments. Every big movement starts out with defeats. The movements that grow and make history have many characteristics, but one thing they share is a surplus of principled men who are not afraid to lose as they work to advance their cause in inhospitable environments.
Treen played a huge role in breaking the Democratic Party's monopoly on the South. He played an important role in organizing U.S. House Republicans toward a conservative, reformist model in the late 1970s to help lay the groundwork for the Reagan presidency. He planted the seeds of reform in Louisiana government.